vampire video speed vs dedicated RTG cards

[wawrzon]

im not sure it this is still the case but initial implementation or rtg on vampire was likely simple framebuffer, without any accel laike blitter, as thomas says. now it might be they have implemented some accelerated memory copy functionality into the core, maybe even masked and such, but i dont know it.

another issue is that vampire shares the same bus to memory for cpu and rtg, so it can starve with higher resolutions and frequencies, while cpu is doing much memory access. the solution to this is as far as im aware a lower rtg frequency, as long as the hdmi display device supports it.

[wawrzon]

The ultimate is to use FPGA based gfx card, like the mnt va2000, along with vampire

actually it is better to use local rtg on the same fpga (which vampire already provides, as much as va2000) rather than behind (by todays standards) slow bus.

[wawrzon]

Yes, and then we replace the Amiga itself with an FPGA board...

It IS getting a little weird.

why? to each his own. while i d like to have an fpga expansion for my amiga (i dont have one) others may favor a new stadalone compatible system.

what it boils down to is to hold to most sommon denominator as closely as possible to be able to address and serve the widest fraction of audience, which is the suers of the genuine amiga (68k) software.

[wawrzon]

blah blah blah..

[wawrzon]

byte me ;-)

[wawrzon]

That's something I'd never considered before,.... the shared RAM bandwidth for "CPU" and video/rtg. Its no wonder benchmarks on the forum are restricted to 640*480 and 800*600.... they'd give better performance. The higher the resolution the slower both graphics and "CPU" will perform.

yes, i think this is the reason. might be considered a hardware flaw and maybe to be corrected in future implementations. likely there is pros and contras using unified versus separate ram for main memory and rtg.